Reflected radio frequency (RF) or acoustic waves may be used to determine the location of an object that reflects such waves, i.e., a “reflector”. Various algorithms have been developed, for use when there are one or more reflectors and for use in two-dimensional as well as three-dimensional space. One approach uses the travel time of the reflected signal to compute the length of the path of the signal from transmitter to the reflector(s) to receiver. Once the path lengths are known, mathematical and geometric techniques are used to locate the object.
Traditional algorithms are easy and straightforward when there is a single reflector. However, in a space crowded with reflectors, such as an indoor space, traditional algorithms are less satisfactory.